It’s a question of scale. Methane is useful fuel, so leaks are an exception rather than the most common result. Spilled gasoline when fueling your car also results in atmospheric CO2, but you produce vastly more CO2 from what ends up in your tank.
The Methane being leaked is 86x more potent than co2 over 20 years and 34x more potent over 100 years.
At 1% leakage todays natural gas emissions don't gain a climate advantage over coal until around 2100. At 2% leakage todays natural gas emissions are still significantly worse than coal in 2100.
https://www.technologynetworks.com/applied-sciences/news/glo...
http://theconversation.com/the-us-natural-gas-industry-is-le...